textproduct: Albany

WHAT HAS CHANGED

The hourly PoPs were adjusted for the rest of the afternoon into tonight with the departing low pressure system near Cape Cod. Snow amounts were adjusted slightly based on the NYS Mesonet Cams and observations, where some 1-2" or so amounts for the west/southwest Adirondacks, southern Green and high peaks of the Catskills may occur. Winds were increased tomorrow with the NBM 90th percentile wind and gusts. Also, hourly PoPs were increased from the NBM for the short-wave and lake effect tonight through tomorrow. Low temps were lowered Mon night slightly below the NBM.

KEY MESSAGES

1) A secondary cold front will move across the region tonight, as the low pressure system departs northeast of Cape Cod. Any additional high elevation snowfall will be light.

2) The upcoming week will start out unseasonably cold for April, but temps will moderate back to near or slightly above normal by the mid to late week.

DISCUSSION

KEY MESSAGE 1... A broad mid and upper level trough continues to impact southeast Canada, the Great Lakes Region and the Northeast this afternoon. A low pressure system continues to track northeast along the preliminary cold front along eastern New England. The wave of low pressure that brought the rain and snow is lifting northeast of Cape Cod. The pcpn changed over the snow for elevations greater than 1500 ft with light snow accums noted on numerous NYS web cams especially in the west-southwest Adirondacks, eastern Catskills and portions of the Helderbergs. Expecting 1-2 or so inches over the high peaks, even the southern Green Mtns. The hilltowns at 1500 ft or so could see a half an inch to an inch especially on the grassy surfaces. Locations below 1500 ft may get a coating to a few tenths on the grass. West to northwest winds increase 10-15 mph with some gusts 25-35 mph. Some clearing is expected in the wake of the initial low. A secondary cold front will bring another surge of cold advection and some lake effect snow showers/flurries especially for the western Adirondacks and southern Greens tonight. A light coating to few tenth are possible. With the cold advection and H850 temps falling 1-2+ STDEVS below normal, as lows fall back into the 20s to lower 30s. The winds should dry out the roads, but be on the lookout for a few slick spots.

The week will open with chilly temps, as the cyclonic flow associated with the upper level trough persists. Another weak disturbance moving through the base of the trough may bring some isolated to widely scattered snow and rain/snow showers to locations from the Capital Region, southern VT south and east. Not expecting much in the way of accumulations, though we did raise PoPs into the slight chance to low chance range (15-30%). H850 temps will be around -10C, which are a couple STDEVs below normal for April. High temps will be close to 15 degrees below normal. Highs will be in the 40s in the valleys, as well as the southern Taconics and NW CT with 30s over the higher terrain. High pressure builds in Mon night with mostly clear/clear skies and light to calm winds for ideal radiational cooling. Lows will be in the mid teens to mid 20s across the region. This would be a hard freeze, but the growing season does officially begin in the valley areas and NW CT until May 1st.

KEY MESSAGE 2... High pressure builds in from northern New England and the Mid Atlantic Region with partly to mostly sunny skies on Tue, as max temps will will be slightly warmer, but still run below normal by 5-10 degrees with highs in the 40s to lower 50s. Another short-wave dives across the region in northwest flow aloft with a slight to low chance of rain/snow showers Tue night into Wed morning. Not much is expected in terms of snow accums with little low-level moisture to work with. A weak sfc trough and a warm front move through with a slight uptick for temps on Wed closer to normal readings with mid 50s to near 60F in the valleys and 40s to around 50F over the mtns and hills. Ridging builds in from the west to southwest for Thu into most of Fri for potentially a dry period with temps warming near to slightly above normal readings based on the NBM and WPC guidance. A disturbance in west to northwest flow and a warm front may bring some scattered showers back to forecast area for late Fri into the weekend with seasonable late April temps. There continues to be some uncertainty on the placement of the ridging and subsequent disturbances moving along the rim of the ridge in the ensembles and long term guidance for next weekend.

AVIATION /18Z SUNDAY THROUGH FRIDAY/

Through 18Z Monday...Flight conditions continue to be MVFR/IFR for KGFL/KALB/KPOU/KPSF early this afternoon with periods of rain and snow with the departing low pressure system near Cape Cod. The IFR conditions are cigs/vsbys at KPOU/KPSF...and where vsbys and cigs are reduced due to some wet snow at KPSF. Expect an improvement to high MVFR/low VFR conditions to occur between 20-22Z/Sun for KALB/KGFL/KPOU with rain diminishing. KPSF may have lingering MVFR cigs close to 00Z/Mon. Tonight, expect the skies to become mostly clear to partly cloudy with VFR conditions. However, in the wake of a secondary cold front, another upper level disturbance will approach Monday morning with mid and high clouds increasing. Bases may lower to 3.5-5 kft AGL by the late morning with a few rain/snow showers approaching KPOU/KPSF prior to 18Z/Mon.

The winds will vary from the north to west 8-15 KT this afternoon with some gusts 20-25 KT at KALB/KPSF. The winds will decrease from the west to northwest at less than 10 KT overnight. Expect the winds to increase from the west/northwest around 10 KT in the late morning with some gusts around 20 KT at KALB.

Outlook...

Monday Night to Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: Low Operational Impact. Slight Chance of SHRA. Wednesday to Friday: No Operational Impact. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.